PlaySudoku.us
Hard · Puzzle #540
1
2
6
7
8
1
5
8
8
4
6
3
6
1
2
7
9
7
8
4
1
6
3
2
6
5
8
7
"Judge a man by his questions rather than by his answers." — Voltaire
"Judge a man by his questions rather than by his answers." — Voltaire
Network flow algorithms can solve special classes of Sudoku more efficiently than general backtracking.
Network flow algorithms can solve special classes of Sudoku more efficiently than general backtracking.